System and method for operating light processing electronic devices

ABSTRACT

A system and method for operating an electronic device used in light processing. A method comprises altering a spatial relationship between a spatial light modulator (SLM) and a light incident on the SLM, shifting light modulator states of a first portion of light modulators to a second portion of light modulators, and placing a third portion of light modulators in the SLM into a performance degradation-reducing mode. The amount of shifting performed is proportional to the amount of change in the spatial relationship. The method allows for a change in light modulators used to modulate the light, thereby preventing the overuse of some of the light modulators, which may help to prevent degradation of the light modulators. The performance degradation reducing mode may help to further reduce or even reverse the performance degradation of the light modulators.

This application is a divisional of application Ser. No. 12/104,279,filed Apr. 16, 2008.

TECHNICAL FIELD

The present invention relates generally to a system and method for lightprocessing, and more particularly to a system and method for operatingan electronic device used in light processing.

BACKGROUND

In general, spatial light modulators (SLM), such as digital micromirrordevices (DMD), deformable micromirrors, liquid crystal on silicon(LCOS), ferroelectric liquid-crystal-on-silicon, reflective,transmissive, and transflective liquid crystal displays (LCD), and soforth, contain a large number of individual light modulators. SLMs havebeen used for creating images for use in image display systems. Inaddition to displaying images, these SLMs may also be used in otherapplications wherein there is a need to optically process light.

An example of such an application is optical networking. In opticalnetworking, SLMs may be used for optical switching, optical signalattenuation, and so on. Light modulators in an SLM may be used toreflect or pass light to various positions to perform optical switching,while in optical signal attenuation, some light modulators in the SLMmay be configured to not reflect or pass light to attenuate the opticalsignal. For example, if the SLM is a DMD, then micromirrors in the DMDmay be pivoted to a desired position in order to switch an incominglight beam, while to attenuate an optical signal, a number of themicromirrors in the DMD may be pivoted away from an intended target tocause a loss in optical signal power, wherein the loss in optical signalpower may be dependent on a pattern of the micromirrors and the numberof micromirrors in the pattern pivoted away from the intended target.

In optical networking applications, it may be necessary to keep thelight modulators of an SLM in a specified state for an extended periodof time, sometimes on the order of months or years. Therefore, it may bepossible to cause degradation, such as permanent burn-in, of the lightmodulators by having them maintain a single state for the extendedamount of time. Furthermore, the power density of the light used inoptical networking applications may be higher than that of light used inimage display applications. The greater power density may lead togreater operating temperatures, which may help to further accelerate theperformance degradation of the light modulators. Degradation of lightmodulators may not be a significant problem in image displayapplications since the light modulators tend to rapidly change stateswhile displaying images and not remain in a single state for an extendedperiod of time. In some SLM technologies, such as the DMD, theperformance degradation can be reduced or eliminated by operating thepixels for a period of time in an opposite state or by cycling throughstates.

SUMMARY OF THE INVENTION

These and other problems are generally solved or circumvented, andtechnical advantages are generally achieved, by embodiments of a systemand a method for operating an electronic device used in lightprocessing.

In accordance with an embodiment, a method for operating an electronicdevice having a spatial light modulator (SLM), the SLM having aplurality of light modulators, is provided. The method includes alteringa spatial relationship between the SLM and a light incident on the SLM,shifting light modulator states of a first portion of light modulatorsto a second portion of light modulators, and placing a third portion oflight modulators in the SLM into a performance degradation-reducingmode. The shifting is proportional to an amount of the alteringperformed on the spatial relationship.

In accordance with another embodiment, an electronic device is provided.The electronic device includes a light source configured to producelight, a set of optics elements positioned in a light path of the lightsource after the light source, a spatial light modulator positioned in alight path of the light source after the light source and the set ofoptics elements, a position shifter that moves the spatial lightmodulator or an optics element in the set of optics elements to change aspatial relationship between the spatial light modulator and the light,and a controller electronically coupled to the spatial light modulatorand to the position shifter. The set of optics elements opticallymanipulates the light, the spatial light modulator performs opticallight processing on light incident on its surface, and the controllerloads light modulator states into the spatial light modulator andchanges light modulator states so that light modulator states of lightmodulators illuminated by the light remain substantially the same beforeand after the change in the spatial relationship between the spatiallight modulator and the light.

In accordance with another embodiment, a method of manufacturing anelectronic device is provided. The method includes installing a lightsource configured to generate light, installing a spatial lightmodulator in a light path of the electronic device after the lightsource, installing optical elements in the light path of the electronicdevice, installing a position shifter to move the spatial lightmodulator or an optical element, and installing a controller. Thecontroller controls the spatial light modulator so that a first patternof light modulator states illuminated by the light prior to a moving ofthe spatial light modulator or the optical element is substantiallyequal to a second pattern of light modulators illuminated by the lightafter the moving of the spatial light modulator or the optical element.

An advantage of an embodiment is that degradation of light modulators ina spatial light modulator may be prevented, thereby potentiallyextending the useful lifespan of a product containing the spatial lightmodulator.

A further advantage of an embodiment is that the performance of theproduct containing the spatial light modulator is not significantlyimpacted while preventing degradation of the light modulators.

The foregoing has outlined rather broadly the features and technicaladvantages of the present invention in order that the detaileddescription of the embodiments that follow may be better understood.Additional features and advantages of the embodiments will be describedhereinafter which form the subject of the claims of the invention. Itshould be appreciated by those skilled in the art that the conceptionand specific embodiments disclosed may be readily utilized as a basisfor modifying or designing other structures or processes for carryingout the same purposes of the present invention. It should also berealized by those skilled in the art that such equivalent constructionsdo not depart from the spirit and scope of the invention as set forth inthe appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the embodiments, and the advantagesthereof, reference is now made to the following descriptions taken inconjunction with the accompanying drawings, in which:

FIG. 1 a is a diagram of an optical networking device;

FIG. 1 b is a diagram of a top view of a surface of an SLM;

FIG. 1 c is a diagram of a side view of a DMD;

FIG. 1 d is a diagram of a side view of a packaged DMD;

FIG. 1 e is a diagram of a side view of a packaged DMD;

FIG. 1 f is a diagram of a top view of a surface of an SLM showingindividual light modulator states;

FIG. 2 is a diagram of an optical networking device;

FIG. 3 a is a diagram of an optical networking device including aposition shifter for reducing degradation of light modulators;

FIG. 3 b is a diagram of an optical networking device including aposition shifter for reducing degradation of light modulators;

FIG. 4 a is a diagram of an optical networking device including aposition shifter for reducing degradation of light modulators;

FIG. 4 b is a diagram of an optical networking device including aposition shifter for reducing degradation of light modulators;

FIGS. 5 a through 5 c are diagrams of a top view of an SLM showing theshifting of a light incident on the surface of the SLM;

FIG. 5 d is a diagram of a top view of an SLM showing several possibleshifts of a light incident on the surface of the SLM;

FIG. 6 is a diagram of an algorithm for use in operating an electronicdevice to reduce degradation of light modulators in the electronicdevice;

FIGS. 7 a and 7 b are diagrams of shifting activity versus time, showingdifferent possible ways to reduce degradation of light modulators;

FIG. 8 is a diagram of a sequence of events in the manufacture of anelectronic device; and

FIGS. 9 a through 9 d are diagrams of a top view of an SLM showing theshifting of light incident on the surface of the SLM.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The making and using of the embodiments are discussed in detail below.It should be appreciated, however, that the present invention providesmany applicable inventive concepts that can be embodied in a widevariety of specific contexts. The specific embodiments discussed aremerely illustrative of specific ways to make and use the invention, anddo not limit the scope of the invention.

The embodiments will be described in a specific context, namely anoptical networking device utilizing a digital micromirror device (DMD)to perform optical light processing. The invention may also be applied,however, to other optical networking devices utilizing other spatiallight modulators, such as deformable micromirrors, liquid crystal onsilicon (LCOS), ferroelectric liquid-crystal-on-silicon, reflective,transmissive, and transflective liquid crystal displays (LCD), and soforth. Additionally, other types of micro-electrical-mechanical systems(MEMS) may be used in place of the spatial light modulators.Furthermore, the invention may also be applied to other applicationswherein the entirety of a spatial light modulator's surface is notdedicated to optical light processing. Examples of such applications mayinclude optical spectroscopy, wherein the spatial light modulator, suchas a DMD, may be used as a gating element for selecting wavelengths aspart of a spectrometer. The mirrors in the DMD may be used to obtain thespectral content of incoming light. Another example of an applicationmay be in image display wherein the spatial light modulator displays animage or set of images for an extended period of time.

With reference now to FIG. 1 a, there is shown a diagram illustrating anoptical networking device 100. The optical networking device 100includes a spatial light modulator (SLM) 105. The SLM 105 may be used toperform optical light processing, such as light steering, lightswitching, optical signal attenuation, and so forth. Examples of the SLM105 may include DMDs, deformable micromirrors, LCOS, ferroelectricliquid-crystal-on-silicon, reflective, transmissive, and transflectiveliquid crystal displays (LCD), and so forth. The optical networkingdevice 105 also includes a first light collimator 110 that may be usedto make the light rays parallel, such as light rays from an opticalfiber, for example, a single mode fiber.

The collimated light from the light collimator 110 may then be separatedinto light having different wavelengths by a first diffraction grating115. In addition to separating the light into different wavelengths, thefirst diffraction grating 115 may also steer the light. Light from thefirst diffraction grating 115 may then be individually focused onto thesurface of the SLM 105 by a set of first optics elements 120. The set offirst optics elements 120 may be designed so that light of differentwavelengths may focus onto different portions of the surface of the SLM105. The set of first optics element 120 may comprise one or moreoptical lenses, filters, mirrors, and other optical processingcomponents.

The light may focus on a portion of the surface of the SLM 105 having asize of roughly N×M light modulators illuminating the light modulators,where N and M are integer numbers. The light modulators illuminated bythe light may be used to optically process the light, such as performlight steering, light switching, optical power attenuation, and soforth, with the states of the light modulators in the N×M lightmodulator sized portion of the surface of the SLM 105 being individuallycontrolled or set to the same state.

FIG. 1 b illustrates a top view of the surface of the SLM 105. As shownin FIG. 1 b, four incoming light beams are reflected off the surface ofthe SLM 105 with the reflection depending on the state of the individuallight modulators. For example, a first incoming light beam 155 may bereflected off the surface of the SLM 105 to produce a first reflectedlight beam 156 with a first angle, and a second incoming light beam 160may be reflected off the surface of the SLM 105 to produce a secondreflected light beam 161 with a second angle. The first angle may bedifferent from the second angle.

Turning back now to FIG. 1 a, light reflecting from the surface of theSLM 105 may then receive additional processing by a set of secondoptical elements 121. The set of second optical elements 121 may refocusthe light reflected from the surface of the SLM 105 onto a seconddiffraction grating 116, for example. The second diffraction grating 116may recombine the individual wavelengths of light back into aparallelized beam of light and redirect the parallelized beam of lightonto the second light collimator 111. The second light collimator 111may focus the light into an output optical fiber.

Collectively, the first light collimator 110, the first diffractiongrating 115, and the set of first optical elements 120 may be referredto as injection optics 125 since they may be used for injecting incominglight onto the surface of the SLM 105. Similarly, the set of secondoptical elements 121, the second diffraction grating 116, and the secondlight collimator 111 may be referred to as collection optics 126 sincethey may be used to collect light reflected off the surface of the SLM105. Although shown in FIG. 1 a as different sets of optical elements,the injection optics 125 and the collection optics 126 may also beimplemented as a single set of optical elements.

FIG. 1 c illustrates a detailed view of a portion of the surface of theSLM 105, wherein the SLM 105 is a DMD. As shown in FIG. 1 c, themicromirrors of a DMD may function in binary operation mode and eachmicromirror may pivot to one of two positions depending on the state ofa memory cell associated with the micromirror. For example, micromirror170 may be in a first position, such as −15 degrees, for example, andmicromirror 175 may be in a second position, such as +15 degrees, forexample. The values of −15 degrees and +15 degrees are only exemplaryvalues for discussion purposes and actual angles may vary. Furthermore,a DMD may function in analog operation mode, wherein micromirrors in theDMD may pivot to many positions in response to a number of signalmagnitudes and electrostatic potentials. An incoming beam of light 180having an incoming angle of zero degrees may then reflect off areflective surface of the micromirrors in the DMD. The incoming beam oflight 180 reflecting off the surface of micromirror 170 is shown aslight beam 181 and may be at −30 degrees while the incoming beam oflight 180 reflecting off the surface of micromirror 175 is shown aslight beam 182 and may be at +30 degrees, for example.

FIG. 1 d illustrates a side view of a portion of a packaged SLM 105,wherein the SLM 105 is a DMD. As shown in FIG. 1 d, the micromirrors ofa DMD may be in binary operation mode and each micromirror may pivot toone of two positions depending on the state of a memory cell associatedwith the micromirror. The micromirrors shown, such as the micromirror175, are pivoted to one position. A light beam 185 passes through anoptically transparent top 186 of the DMD and reflects off themicromirrors. After reflecting off the micromirrors, the light beam 185once again passes through the optically transparent top 186 as it exitsthe DMD.

FIG. 1 e a side view of a portion of a packaged SLM 105, wherein the SLM105 is a DMD. As shown in FIG. 1 e, the micromirrors of a DMD may be inbinary operation mode and each micromirror may pivot to one of twopositions depending on the state of a memory cell associated with themicromirror. Some of the micromirrors shown, such as the micromirror170, are pivoted to a first position, while some of the micromirrors,such as the micromirror 175, are pivoted to a second position. A lightbeam 185 passes through the optically transparent top 186 of the DMD andreflects off the micromirror 175. The micromirror 175 may be positionedso that the light beam 185 reflects off a reflective stripe 187 ratherthan passing through the optically transparent top 186 and exiting theDMD. The light beam 185 reflects off the reflective stripe 187 ontoadditional micromirrors, such as the micromirror 170. The light beam 185then reflects off the micromirror 170 and then passes through theoptically transparent top 186, exiting the DMD.

FIG. 1 f illustrates a top view of a portion of the surface of the SLM105. FIG. 1 f illustrates a circle 190 that may be representative of alight beam incident on the surface of the SLM 105. The circle 190 coversan area roughly the size of 12×12 light modulators. Some of the lightmodulators, such as light modulator 195, may be in a state to reflectthe light beam 190 to a desired position, such as toward the set ofsecond optics elements 121, while some of the light modulators, such aslight modulator 196, may be in a state to reflect the light beam 190away from the desired position. The light modulators reflecting lightaway from the desired position, such as the light modulator 196, may beused to attenuate the optical signal power of the light beam 190. Thegreater the number of light modulators in a state like the lightmodulator 196, the lower the optical signal power of the light beam 190reaching the set of second optics elements 121, for example.

Although shown in FIGS. 1 a, 1 b, 1 c, and 1 d to be reflective innature, the SLM 105 may also be transmissive, wherein the lightmodulators in the SLM 105 may pass light or block light depending ontheir state. Therefore, the discussion of reflective SLMs in general,and DMDs in particular, should not be construed as being limiting toeither the scope or the spirit of the embodiments.

Data transmitted over an optical network may require that the opticalnetwork not change for an extended period of time. Once configured, theoptical network may not change over periods as long as months or years.Keeping light modulators of an SLM in a fixed state for an extendedperiod of time and usually with high operating temperatures may resultin degradation of light modulators in the SLM. For example, continuoususe at elevated temperatures may degrade the material used in liquidcrystal displays. Additionally, mechanical structures used in MEMS maybe susceptible to performance degradation at high operatingtemperatures. To further complicate matters, the operation of theoptical network is generally continuous with little to no down time thatmay be used to help prevent or reverse degraded performance of the lightmodulators in the SLM.

FIG. 2 illustrates an optical networking device 200. Like the opticalnetwork device 100 (FIG. 1 a), the optical networking device 200 usesthe SLM 105 to perform optical light processing. However, the opticalnetworking device 200 uses a mirror 205 to reflect light towards andaway from the SLM 105. A fold mirror may be an example of a type ofmirror that may be used to implement the mirror 205. A potentialadvantage of the use of the mirror 205 may be a reduction in thephysical size of the optical network device 200, since the mirror 205allows the light to traverse a necessary optical distance to achievedesired optical performance while reducing the physical distancetraveled by the light.

Since keeping light modulators in the SLM 105 in a fixed state for anextended amount of time at elevated operating temperatures may lead todegraded light modulators, one possible technique to help preventdegradation of the light modulators is to change the light modulatorsused to perform optical light processing over time. By doing this, thelight modulators may not be used for extended periods of time. However,since an optical network tends to be in continuous operation, it may bedifficult to change the light modulators used to perform optical lightprocessing without negatively impacting the performance of the opticalnetwork.

FIG. 3 a illustrates an optical networking device 300, wherein theoptical networking device 300 includes a position shifter 302 forreducing degradation of light modulators due to overuse. One method tochange the light modulators used to perform optical light processing inan SLM may be to physically move the SLM containing the lightmodulators. As with the optical networking device 100 discussedpreviously, the optical networking device 300 includes the SLM 105 thatmay be used to perform optical light processing. The optical networkingdevice 300 also includes a first light collimator 110 that may be usedto parallelize light, the first diffraction grating 115 that may be usedto separate light into different wavelengths, the set of first opticselements 120 that may be used to focus light onto the surface of the SLM105, the set of second optics elements 121 that may be used to refocuslight reflected from the surface of the SLM 105 onto the seconddiffraction grating 116, and a second light collimator 111 that may beused to focus light from the second diffraction grating 116 into anoutput optical fiber.

The position shifter 302 may operate by moving the SLM 105. The positionshifter 302 includes a translation stage 305 that may be used to movethe SLM 105. The translation stage 305 may be a movable surface coupledto a motor(s) 310. The motor 310 may be able to move the translationstage 305 along one or two axes forming a plane. Preferably, thetranslation stage 305 may move the SLM 105 in such a manner that itremains in the same plane as the surface of the SLM 105. This mayprevent the need to adjust the focus of the set of first optics elements120 and the set of second optics elements 121 as the translation stage305 moves the SLM 105.

As the motor 310 moves the translation stage 305 (and hence the SLM 105)along one or two axes describing the plane, it may be necessary tochange the state of the light modulators in the SLM 105 so thateffectively the light being optically processed encounters substantiallythe same configuration of light modulators as the SLM 105 is movedunderneath the light. This may be achieved by a processor 315 coupled tothe SLM 105 and to the motor 310. The processor 315 may change thestates of the light modulators moving into the light in a mannerconsistent with the light modulators moving from under the light, i.e.,light modulator states of the light modulators illuminated by the lightremain substantially consistent before and after the SLM 105 is moved.For example, a pattern of light modulator states illuminated by thelight prior to the move will remain substantially equal to a pattern oflight modulator states illuminated by the light after the move. Acontroller, an application specific integrated circuit, a state machine,and so forth, may be used in place of the processor 315. For example, ifthe SLM 105 is being moved from left to right, then the processor 315may change the states of the light modulators on a left edge of thelight to correspond to the state of the light modulators on a right edgeof the light. A memory 320 may be used to store the state of the lightmodulators in the SLM 105.

FIG. 3 b illustrates an optical networking device 350, wherein theoptical networking device 350 includes a system for reducing degradationof light modulators due to overuse. The optical networking device 350may be similar to the optical network device 200 with the inclusion ofthe translation stage 305 and the motor 310. Like the optical networkingdevice 300, the optical networking device 350 includes the processor 315and the memory 320, but they are omitted in the diagram to maintainsimplicity.

FIG. 4 a illustrates an optical networking device 400, wherein theoptical networking device 400 includes a position shifter 402 forreducing degradation of light modulators due to overuse. Another methodto substitute the light modulators used to perform optical lightprocessing may be to change the position of the light being processed onthe surface of an SLM, such as the SLM 105. It may be possible to changethe position of the light by adjusting the optical components of theoptical networking device 400. The optical components of the opticalnetworking device 400 includes a first light collimator 110 that may beused to parallelize light, the first diffraction grating 115 that may beused to separate light into different wavelengths, the set of firstoptics elements 120 that may be used to focus light onto the surface ofthe SLM 105, the set of second optics elements 121 that may be used torefocus light reflected from the surface of the SLM 105 onto the seconddiffraction grating 116, and a second light collimator 111 that may beused to focus the light onto an output optical fiber.

In cases such as shown in FIG. 4 a, wherein there are separate opticsfor an incoming light and an outgoing light, both the incoming light andthe outgoing light may be turned, rotated, shifted, or a combinationthereof. While it may be possible to change the position of the light onthe surface of the SLM 105 by turning, rotating, shifting, or acombination thereof the first diffraction grating 115 and the seconddiffraction grating 116 and/or the set of first optical elements 120 andthe set of second optical elements 121, it may be preferred that themanipulation be limited to the first diffraction grating 115 and thesecond diffraction grating 116. Since the set of first optics elements120 and the set of second optics elements 121 may contain multipleoptical elements that are positioned with strict tolerances on position,orientation, and so forth, manipulation of some or all of the opticalelements in the set of first optics elements 120 and the set of secondoptics elements 121 may result in a degradation of the performance ofthe optical networking device 400. However, if the performance of theset of first optics elements 120 and the set of second optics elements121 may be maintained after any turning, rotating, shifting, or acombination thereof, then the set of first optics elements 120 and theset of second optics elements 121 may also be used in the changing ofthe position of the light on the surface of the SLM 105.

The position shifter 402 may turn, rotate, shift, or a combinationthereof, the first diffraction grating 115 and the second diffractiongrating 116 (and/or the set of first optics elements 120 and the set ofsecond optics elements 121) through the use of a motor 405 coupled tothe first diffraction grating 115 and a motor 406 coupled to the seconddiffraction grating 116. The motor 405 may turn, rotate, shift, or acombination thereof, the first diffraction grating 115 in such a mannerthat a spatial relationship between the first diffraction grating 115and the set of first optics elements 120 is maintained. Similarly, themotor 406 may turn, rotate, shift, or a combination thereof, the seconddiffraction grating 116 in such a manner that a spatial relationshipbetween the second diffraction grating 116 and the set of second opticselements 121 is maintained. By maintaining the spatial relationshipbetween the first diffraction grating 115 and the set of first opticselements 120 and the second diffraction grating 116 and the set ofsecond optics elements 121, it may alleviate any need to makeadjustments to the optical elements in the set of first optics elements120 and the set of second optics elements 121, such as adjusting thefocus of the set of first optics elements 120 or the set of secondoptics elements 121.

It may be possible to couple the first diffraction grating 115 and thesecond diffraction grating 116 together so that a single motor may beused to turn, rotate, shift, or a combination thereof, both diffractiongratings. Additionally, it may also be possible to use a singlediffraction grating and a single set of optics elements for both theincoming light and the outgoing light. In such a configuration, a motormay need to only turn, rotate, shift, or a combination thereof, a singlediffraction grating and/or a single set of optics elements. An exampleof such a configuration may be a system that uses a single diffractiongrating and focusing optics that overlaps the input light and theoutgoing light so that the outgoing light enters the same optical fiberthat it arrived in. Another example of such a configuration may be asystem wherein the incoming light and the outgoing light are slightlyoffset so that the outgoing light enters an optical fiber slightlyoffset from the incoming light. The optical fiber in this configurationmay be an array of closely spaced optical fibers.

As the position of the light on the surface of the SLM 105 is changed,it may be necessary to change the state of light modulators in the SLM105 so that effectively the light being optically processed encounterssubstantially the same configuration of light modulators as the lightmoves across the surface of the SLM 105. This may be achieved by aprocessor 410 coupled to the SLM 105 and to the motor 405 and the motor406. The processor 410 may change the states of the light modulatorsmoving into the light in a manner consistent with the light modulatorsmoving from under the light as the position of the light on the surfaceof the SLM 105 changes. A memory 415 may be used to store the state ofthe light modulators in the SLM 105.

FIG. 4 b illustrates an optical networking device 450, wherein theoptical networking device 450 includes a system for reducing degradationof light modulators due to overuse. The optical networking device 450may be similar to the optical networking device 200 with the inclusionof multiple position shifters. The optical networking device 450includes two position shifters, a position shifter 402 to alter theposition of the first diffraction grating 115 and the second diffractiongrating 116 and a position shifter 403 to alter the position of themirror 205 using a motor 407. Like the optical networking device 400,the optical networking device 450 includes the processor 410 and thememory 415, but they are omitted in the diagram to maintain simplicity.

In addition to moving/shifting/turning/rotating the SLM 105 as shown inFIGS. 3 a and 3 b and moving/shifting/turning/rotating opticalcomponents as shown in FIGS. 4 a and 4 b, it may be possible to combineboth the moving/shifting/turning/rotating of the SLM 105 and themoving/shifting/turning/rotating of optical components to periodicallyreplace the light modulators used to perform optical light processing.By combining both techniques, it may be possible to effectively move theposition of the light beam on the surface of the SLM 105 by a greateramount. Additionally, if the moving/shifting/turning/rotating of the SLM105 or an optical component may occur in only a single axis (to simplifydesign and implementation, for example), then combining themoving/shifting/turning/rotating of both the SLM 105 and the opticalcomponents may enable the effective moving of the position of the lightbeam on the surface of the SLM 105 along two axes.

FIG. 5 a illustrates a view of a surface of a portion of an SLM, such asthe SLM 105, that is part of an optical networking device. The diagramshown in FIG. 5 a illustrates a light beam incident on the surface ofthe SLM 105 with the position of the light beam on the surface of theSLM 105 shown as circle 505. Light modulators, such as light modulator510, in the circle 505 may be illuminated by the light beam and may beconfigured to modulate light from the light beam in a manner consistentwith proper operation of the optical networking device. Other lightmodulators, such as light modulator 515, outside of the circle 505 maybe in a rest state or a don't care state if they are not being used tomodulate light.

FIG. 5 b illustrates a view of a surface of a portion of the SLM 105,wherein the position of the light beam has been changed. As shown inFIG. 5 b, the light beam has been shifted or translated to the right,with the position of the light beam on the surface of the SLM 105 shownas circle 520. The amount of the shift is about two light modulators tothe right or about 20% of the total number of light modulators ischanged. The change in the position of the light beam may be as a resultof a shifting of the SLM 105, a shifting of an optical component, or acombination of both. Since the change in position of the light beam issmall (significantly less than the size of the light beam), the state ofa majority of the light modulators 510 do not need to change. Lightmodulators that were in the circle 505 but not in the circle 520, suchas light modulator 525, may be placed into a special mode to reduce,prevent, or reverse any performance degradation that may have arisenfrom extended use. The special mode may involve periodic switches inlight modulator state, rapid light modulator state switching, switchingto a state that is complementary to the state of the light modulator510, or so forth. Since these light modulators, such as the lightmodulator 525, are no longer illuminated by the light beam, their statesmay be changed without impacting the performance of the opticalnetworking device. Light modulators that are in the circle 520 but werenot in the circle 505, such as light modulator 530, may be switched to astate consistent with proper operation of the optical networking device.

FIG. 5 c illustrates a view of a surface of a portion of the SLM 105,wherein the position of the light has been changed. As shown in FIG. 5b, the light beam has been shifted to the right, with the position ofthe light beam on the surface of the SLM 105 shown as circle 535. Lightmodulators that were in the circle 520 but not in the circle 535, suchas light modulator 540, may be placed into a special mode to prevent orreverse any performance degradation that may have arisen from extendeduse. Again, since these light modulators, such as the light modulator525, are no longer illuminated by the light beam, their states may bechanged without impacting the performance of the optical networkingdevice. Light modulators that are in the circle 535 but were not in thecircle 520, such as light modulator 545, may be switched to a stateconsistent with proper operation of the optical networking device. Theshift may be continued until all light modulators originally in thecircle 505 are no longer illuminated by the light beam. After a periodof time, the light beam may be shifted back to positions on the surfaceof the SLM 105 shown as circles 505, 520, 535, and so on.

FIG. 5 d illustrates a view of a surface of a portion of the SLM 105,wherein light from multiple light beams are shining on the surface ofthe SLM 105. The diagram shown in FIG. 5 d illustrates several ways toalter the position of light on the surface of the SLM 105. Light from afirst light beam, shown as circle 550, may be shifted along a horizontalaxis, while light from a second light beam, shown as circle 555, may beshifted along a vertical axis. In addition to altering the position oflight on the surface of the SLM 105 along a single axis, it may bepossible to alter the position of light along two axes. Light from athird beam of light, shown as circle 560, may be shifted along both avertical axis and a horizontal axis. If the shifts are performed equallyalong the two axes, then the shift in the position of light will bealong a 45 degree diagonal. By varying the amount of shifting performedalong the two axes, it may be possible to perform radial shifts. Lightfrom a fourth beam of light, shown as circle 565, may be shiftedradially about a point 570.

In addition to the four regular shifts in the position of light on thesurface of the SLM 105, random shift patterns may also be used. Ingeneral, any form of shifting in the position of light on the surface ofthe SLM 105 may be acceptable as long as the shifting results in acycling in the light modulators used to perform optical lightprocessing. The four different shifts in the position of light on thesurface of the SLM 105 are illustrated together for discussion purposes.Typically, a single type of shift may be performed for all light on asingle SLM surface.

FIG. 6 illustrates an algorithm 600 for use in the reduction ofperformance degradation to light modulators due to overuse. Thealgorithm 600 may execute in a processor, such as the processor 315, theprocessor 410, a controller, an application specific integrated circuit,a controller, or so on. The reduction of performance degradation tolight modulators due to overuse may begin with an altering a spatialrelationship between an SLM and a light beam(s) incident on the surfaceof the SLM (block 605). Altering the spatial relationship between theSLM and the light beam(s) may be accomplished by moving the SLM and/orthe light beam(s). This may be achieved by moving the SLM, the lightbeams, or both.

The SLM may be moved through the use of a translation stage, such as thetranslation stage 305, coupled between the SLM and a motor, such as themotor 310, as shown in FIG. 3 a and FIG. 3 b, for example. The motor 310may move the translation stage 305 (and hence, the SLM) along one or twoaxes describing a plane that may be an extension of the surface of theSLM. The light beams may be moved by manipulating optical components,such as the first diffraction grating 115, the set of first opticselements 120, and the mirror 205, as shown in FIGS. 4 a and 4 b. Theoptical components may be moved by a motor, such as the motor 405 andthe motor 406. The motors 405 and 406 may alter the spatial relationshipbetween the SLM and the light beam(s) by shifting, rotating, turning,and combinations thereof, the optical components. It may be possible tocombine both the moving of the SLM and the light beam(s) to alter thespatial relationship between the SLM and the light beam(s).

Preferably, the altering of the spatial relationship between the SLM andthe light beam(s) should occur in small increments so that theperformance of the optical light processing may not be negativelyimpacted. For example, if the altering of the spatial relationshipbetween the SLM and the light beam(s) involves a shift large enough sothat the optical light processing must temporarily stop, thencommunications in an optical network utilizing the SLM may need to bepaused. Therefore, small shifts that affect 2% to 5% of the lightmodulators may be preferred. For performance critical applications,smaller shifts that affect less than about 1% to 2% of the lightmodulators may be preferred. However, in less sensitive applications,larger shifts resulting in less than 15% to 20% of the light modulatorsbeing affected may be permissible. In terms of actual light modulatorsin the SLM, in performance critical applications, shifts of one lightmodulator at a time may be performed, while for less criticalapplications, shifts of multiple light modulators at a time may bepossible.

Additionally, the altering of the spatial relationship between the SLMand the light beam(s) may occur in rapid succession separated by anextended period without any activity or they may occur with regularity.FIG. 7 a illustrates a plot of shifting activity versus time. A singleimpulse, such as impulse 705, illustrates a single instance where thespatial relationship between the SLM and the light beam(s) is altered.As discussed previously, the altering of the spatial relationship shouldoccur in relatively small increments so that the performance may not benegatively impacted. For discussion purposes, let a single instance ofaltering of the spatial relationship between the SLM and the lightbeam(s) result in about 20% of the light modulators being impacted.Therefore, five successive instances of altering of the spatialrelationship may result in the replacement of the light modulatorspreviously used to perform optical light processing. A first grouping710 highlights five consecutive instances of altering of the spatialrelation, with each instance occurring at least as rapidly as possiblewithout negatively impacting the performance of the optical lightprocessing. The amount of time between impulses in the first groupingmay be about equal or different. FIG. 7 a also illustrates a secondgrouping 715 occurring at a substantially later time. The secondgrouping 715 may continue to shift the light or the SLM further in thesame direction as the first grouping 710 or may shift it back in theopposite direction (or along other possible directions).

FIG. 7 b illustrates a plot of shifting activity versus time. FIG. 7 bdisplays a sequence of impulses, such as impulse 755 and impulse 760,with each impulse representing a single instance where the spatialrelationship between the SLM and the light beam(s) is altered. Theimpulses in the sequence of impulses may be separated by substantiallyequal periods of time or the separation between individual impulses maydiffer. Furthermore, the amount of change in the spatial relationshipbetween the SLM and the light beam(s) may be about equal for each changein the spatial relation or the amount of change may differ for eachchange in spatial relationship.

Turning back to FIG. 6, prior to, during, or after the altering of thespatial relationship between the SLM and the light beam(s), the state ofthe light modulators being used to perform optical processing on thelight beam(s) may be shifted an amount proportional to the altering ofthe spatial relationship between the SLM and the light beam(s) (block610). The shifting of the state of the light modulators may help toensure that, as the spatial relationship between the SLM and the lightbeam(s) is altered, the light processing performed by the lightmodulators is not significantly impacted by the shifting of the SLM, thelight beam(s), or both. The shifting of the state of the lightmodulators may ensure that light modulators illuminated by the lightbeam(s) after the altering of the spatial relationship between the SLMand the light beam(s) are in substantially the same state as lightmodulators illuminated by the light beam(s) prior to the altering of thespatial relationship.

The shifting of the state of the light modulators may depend on how thespatial relationship between the SLM and the light beam(s) is beingaltered. For example, if only the SLM is being shifted, then theshifting of the state of the light modulators may be in a directionsubstantially opposite to the shifting of the SLM. If only the lightbeam(s) is being shifted, then the shifting of the state of the lightmodulators may be in a direction substantially equal to the shifting ofthe light beam(s). If both the SLM and the light beam(s) are beingshifted, then the shifting of the state of the light modulators maydepend on a net result of the shifting of the SLM and the light beam(s).

After the shifting of the state of the light modulators (block 610), thelight modulators formerly being used to perform optical light processingmay be operated in a special operating mode to help prevent or reverseperformance degradation arising from overuse (block 615). For example,if the SLM is a DMD, then the light modulators may be set to a stateopposite their previous state and held in the new state for a period oftime about equal to the amount of time that they were used to opticallyprocess the light beam(s). Alternatively, the light modulators may beset to alternate states with the light modulators holding the state fora specified period of time. In yet another alternative, the lightmodulators may be exercised by cycling through a sequence of states,wherein the sequence of states may be a predetermined sequence, a randomsequence of states, a pseudorandom sequence of states, or so forth.

FIG. 8 is a diagram illustrating a sequence of events 800 in themanufacture of an electronic device using an SLM for optical lightprocessing. The manufacture of the electronic device may begin withinstalling a light source, which may be an optical fiber carrying datain optical form or a light source capable of producing light (block805). The manufacture may continue with installing an SLM, such as aDMD, in the light path of the light source (block 810). After installingthe SLM, optical components may be installed in the light path, betweenthe light source and the SLM (block 815). The optical components mayalso be installed after the SLM. Optical components may include opticselements such as lenses, filters, and so forth, and diffractiongratings. A controller or processor for the electronic device may thenbe installed (block 820).

With the controller installed, the manufacture may continue withinstalling a position shifter (block 825). The installing of theposition shifter may include the installing of a motor (block 830) toenable the moving, shifting, rotating, turning, or a combinationthereof, of the SLM, one or more of the optical components, or both theSLM and one or more of the optical components. If the motor is installedto move, shift, rotate, turn, and so forth, the SLM, a translation stagemay also be installed (block 835). The order of the events in thissequence may be changed, the sequence may be performed in a differentorder, or some of the steps may be performed at the same time to meetparticular manufacturing requirements of the various embodiments of thedisplay plane, for example.

FIGS. 9 a and 9 b are views of a surface of a portion of the SLM 105. Inoptical networking, it may be possible to use an elongated beam of lightin place of a circle of light as shown previously. FIG. 9 a illustratesan elongated beam of light incident on the surface of the SLM 105 withthe position of the elongated beam of light on the surface of the SLM105 shown as an oval 905. The oval 905 had previously been at a positionrepresented as a dashed oval 910 prior to a shift of either theelongated beam of light or the SLM 105 or both. FIG. 9 b illustrates ashift of the elongated beam of light or the SLM 105 or both in acomplementary direction. Generally, depending on application, a widevariety of different shapes of light may be used in optical networking.Therefore, the discussion of circles, elongated beams, ovals, and soforth, should not be construed as being limiting to either the scope orthe spirit of the embodiments.

FIGS. 9 c and 9 d are views of a surface of a portion of the SLM 105,wherein a reflective stripe 187 is shown superimposed on the surface ofthe SLM 105. The presence of the reflective stripe 187 may restrictpermissible shifts in a light or the SLM 105 or both, since a shift thatmay result in the light missing the reflective stripe 187 may lead toundesirable results. FIGS. 9 c and 9 d illustrate ovals, such as oval925 and oval 926, representing elongated beams of light after a shift ofthe elongated beams of light or the SLM 105 or both. Ovals, such as oval930 and oval 931, represent the elongated beams of light prior to theshift. A shift along the reflective stripe 187 may help to ensure thatthe light does not miss the reflective stripe 187.

Although the embodiments and their advantages have been described indetail, it should be understood that various changes, substitutions andalterations can be made herein without departing from the spirit andscope of the invention as defined by the appended claims. Moreover, thescope of the present application is not intended to be limited to theparticular embodiments of the process, machine, manufacture, compositionof matter, means, methods and steps described in the specification. Asone of ordinary skill in the art will readily appreciate from thedisclosure of the present invention, processes, machines, manufacture,compositions of matter, means, methods, or steps, presently existing orlater to be developed, that perform substantially the same function orachieve substantially the same result as the corresponding embodimentsdescribed herein may be utilized according to the present invention.Accordingly, the appended claims are intended to include within theirscope such processes, machines, manufacture, compositions of matter,means, methods, or steps.

1. A method for operating an electronic device having a spatial lightmodulator (SLM), the SLM having a plurality of light modulators, themethod comprising: altering a spatial relationship between the SLM and alight incident on the SLM; shifting light modulator states of a firstportion of light modulators to a second portion of light modulators,wherein the shifting is proportional to an amount of the alteringperformed on the spatial relationship; and placing a third portion oflight modulators in the SLM into a performance degradation-reducing modein which the degradation of the performance of the third portion oflight modulators in the SLM is reduced; wherein the third portion oflight modulators comprises light modulators illuminated by the lightprior to the altering the spatial relationship but not illuminated bythe light after the altering the spatial relationship; and wherein thethird portion of light modulators comprises a range of about less thanone (1) percent to about 20 percent of the first portion of lightmodulators.
 2. An electronic device comprising: a light sourceconfigured to produce light; a set of optics elements positioned in alight path of the light source after the light source, the set of opticselements configured to optically manipulate the light; a spatial lightmodulator having a plurality of light modulators positioned in a lightpath of the light source after the light source and the set of opticselements, the spatial light modulator configured to perform opticallight processing on light incident on its surface; a position shifterconfigured to move the spatial light modulator or an optics element inthe set of optics elements to change a spatial relationship between thespatial light modulator and the light; and a controller electronicallycoupled to the spatial light modulator and to the position shifter, thecontroller configured to load light modulator states into the spatiallight modulator and to change light modulator states so that a firstpattern of light modulator states of light modulators illuminated by thelight before the change in the spatial relationship between the spatiallight modulator and the light is substantially the same as a secondpattern of light modulators illuminated by the light after the change inthe spatial relationship between the spatial light modulator and thelight, and so that light modulator states of light modulators no longerilluminated by the light are set to complementary positions.
 3. Theelectronic device of claim 2, wherein the position shifter comprises amotor configured to move the optics element along a plane substantiallyparallel to a surface of the spatial light modulator containing thelight modulators.
 4. The electronics device of claim 3, wherein theoptics element comprises a diffraction grating or a fold mirror.
 5. Theelectronics device of claim 2, wherein the position shifter comprises: atranslation stage coupled to the spatial light modulator, thetranslation stage to allow the spatial light modulator to move in aplane substantially parallel to a surface of the spatial light modulatorcontaining the light modulators; and a motor coupled to the translationstage, the motor to move translation stage.
 6. A method of manufacturingan electronic device, the method comprising: installing a light sourceconfigured to generate light; installing a spatial light modulatorhaving a plurality of light modulators in a light path of the electronicdevice after the light source; installing optical elements in the lightpath of the electronic device; installing a position shifter to move thespatial light modulator or an optical element; and installing acontroller configured to control the spatial light modulator so that afirst pattern of light modulator states illuminated by the light priorto a moving of the spatial light modulator or the optical element issubstantially equal to a second pattern of light modulators illuminatedby the light after the moving of the spatial light modulator or theoptical element, and so that light modulator states of light modulatorsno longer illuminated by the light are set to complementary positions.7. The method of claim 6, wherein installing the position shiftercomprises installing a motor.
 8. The method of claim 7, wherein theposition shifter moves the spatial light modulator, and whereininstalling the position shifter further comprises installing atranslation stage coupled between the motor and the spatial lightmodulator.
 9. A method for operating an electronic device having aspatial light modulator (SLM) including a plurality of light modulators,the method comprising: directing an incident light beam onto asubplurality of less than all of the light modulators; shifting theposition of the SLM relative to the incident light beam to change thelight modulators making up the subplurality; and changing states of thelight modulators so that the states of the light modulators making upthe subplurality after shifting substantially match the states of thelight modulators making up the subplurality prior to shifting, and sothat light modulators making up the subplurality prior to shifting butnot making up the subplurality after shifting have states that arecomplementary to the states of the same modulators prior to shifting.10. The method of claim 9, wherein shifting the position comprisesshifting the SLM.
 11. The method of claim 10, wherein the lightmodulators are disposed on a surface of the SLM; and shifting the SLMcomprises moving the SLM in a plane substantially parallel to thesurface.
 12. The method of claim 11, wherein moving the SLM in the planecomprises moving the SLM along one or two axes describing the plane. 13.The method of claim 9, wherein the electronic device is an opticalnetworking device.
 14. The method of claim 13, wherein directing theincident light beam comprises directing first and second beams ofdifferent wavelengths onto respective different first and secondsubpluralities of the light modulators; shifting the position of the SLMcomprises shifting the position of the SLM to change the lightmodulators making up the first and second subpluralities; and changingthe states comprises changing the states so that the states of therespective light modulators making up the first and secondsubpluralities after shifting substantially match the states of therespective light modulators making up the first and secondsubpluralities prior to shifting, and so that the respective lightmodulators making up the first and second subpluralities prior toshifting but not making up the first and second subpluralities aftershifting have the opposite states of the same modulators prior toshifting.
 15. The method of claim 14, wherein directing the incidentlight beam comprises separating a composite incident light beam into thefirst and second beams using a first diffraction grating.
 16. The methodof claim 15, further comprising recombining the first and second beamsafter modulation by the respective light modulators of the first andsecond subpluralities using a second diffraction grating.
 17. The methodof claim 16, wherein the SLM is a digital micromirror device, themodulators are micromirrors, the states are positions pivoted by anangle in a direction and the complementary states are positions pivotedby the angle in a second direction.
 18. The method of claim 17, whereinthe angle of the states of the modulators of the first subplurality isdifferent than the angle of the states of the modulators of the secondsubplurality.